This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-141301, filed May 15, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a semiconductor apparatus, and in particular, to a package having an under-fill resin sheet interposed between a wire substrate and a semiconductor chip.
A semiconductor apparatus is of such a type that has a semiconductor package in which a wiring substrate mounting a semiconductor chip is resin sealed with a mold resin. FIG. 10 is a sectional view of a package (CSP: Chip Size (Scale) Package) of a flip chip connection type having a conventional structure.
As a wiring substrate, there is employed an interposer made of a polyimide film (insulation film). A wiring layer 105 such as Cu is provided on a surface of a polyimide film 100. A chip 101 is disposed on the polyimide film 100, and is flip-chip connected to the polyimide film 100. That is, a connection electrode 106 that is formed on a lower face of the chip 101, and is electrically connected to its inside circuit (not shown) is connected to a wiring layer 105 formed on the surface of the polyimide film 100. An under-fill resin sheet 102 made of an epoxy resin or the like is provided between the chip 101 and the polyimide film 100, and a space between them is sealed from the outside. A resin sealing body 104 made of a mold resin such as epoxy resin is provided all over the chip, and the entire chip is sealed from the outside. That is, the resin sealing body 104 made of a mold resin is provided on the chip 101 and on the filling resin sheet 102, and the entire chip is sealed from the outside.
A laminate body made of the polyimide film 100, under-fill resin sheet 102, chip 101, and resin sealing body 104, that is, a package, is mounted on a mount substrate 107. When the package is mounted on the mount package 107, a wiring layer 105 formed on the surface of the polyimide film 100 is connected to a wiring layer 108 such as Cu formed on the surface of the mount substrate 107 via an external terminal 103 made of solder or the like provided at the periphery of the polyimide film 100.
The chip 101 and under-fill resin sheet film 102 are substantially identical to each other in size, and the under-fill resin sheet 102 does not protrude from a side face of the chip 101. The entire chip is sealed by the resin sealing body 104 made of a mold resin such as epoxy resin formed to be covered on the polyimide film 100. The mount height of the package is 0.5 (Max), and the thickness of the chip 101 is about 0.2 mm.
FIG. 11 is a sectional view illustrating a state in which the package of the semiconductor apparatus shown in FIG. 10 is mounted on the mount substrate 107. A terminal 103 of the polyimide film 100 is connected to a wire 108 on the mount substrate 107 (FIG. 11).
After the package of the semiconductor apparatus shown in FIG. 10 has been mounted on the mount substrate 107, a mount TCT (Temperature Cycling Test) test is carried out. When this test is carried out, a stress is experienced in the solder of the terminal 103 due to the difference in thermal expansion coefficients between the members, a crack occurs within the solder, finally resulting in electrical disconnection. In the package having a structure shown in FIG. 10, a solder portion is mainly disconnected in a comparatively small number of test cycles because the Young""s modulus of mold resin is particularly high due to the difference in the thermal expansion coefficient between the mount substrate and the mold resin.
In addition, reliability tests for the semiconductor apparatus include a re-flow test for damping the package, thereby carrying out re-flow. This test is conducted to find out whether or not a reliability-error occurs in the package when re-flow is applied, due to water in the package contained when it is damped. In the package shown in FIG. 10, as shown in FIG. 12, there is no escape path through which water accumulated by the under-fill resin sheet 102 is effectively discharged to the outside during damping. Thus, when re-flow is applied, a crack occurs with the under-fill resin sheet 102, and the re-flow resistance is lowered.
In addition, in a CSP package of flip chip type, as shown in FIG. 13, a mold resin of the resin sealing body 104 is loaded on the wiring layer 105 such as Cu formed on the polyimide film 100. An adhesion between Cu and the mold resin is so lowered as to be prone to deterioration, thus causing their separation. In manufacture of the CSP package of flip chip type, the chip 101 is mounted after the under-fill resin sheet 102 has been pasted on a large polyimide film 100, and then, the entirety is resin sealed with the mold resin 104. Then, there is adopted a method for carrying out dicing cut into individual pieces in units of chip 101. When cut into individual pieces, a separation occurs between Cu and the mold resin.
FIG. 14A and FIG. 14B, FIG. 15A and FIG. 15B, FIG. 16A and FIG. 16B, and FIG. 17A and FIG. 17B are plan views and sectional views of laminate structures in manufacturing processes, for illustrating a conventional manufacturing method comprising the steps of: forming a laminate body of the polyimide film 100, under-fill resin sheet 102, chip 101, and mold resin 104, and cutting the formed laminate body along a package region, thereby forming a plurality of semiconductor apparatuses. FIG. 14B, FIG. 15B, FIG. 16B, and FIG. 17B are sectional views of one package region.
As a wiring substrate, there is employed an interposer made of the polyimide film 100. A package region is partitioned in plurality on the wiring substrate 100 having the polyimide film 100 provided on the surface (FIG. 14A). Each package region is a unit region in which one chip is mounted. Each of the under-fill resin sheets 102 is mounted on each package region of the polyimide film 100 (FIG. 14B). Next, one chip 101 is disposed on each under-fill resin sheet 102, and is pasted by thermal pressure welding (FIG. 15A). Next, the entirety of the polyimide film 100 is covered with the mold resin 104 (FIG. 15B). Then, a laminate body of the polyimide film 100, under-fill resin sheet 102, chip 101, and mold resin 104 is cut into individual pieces along individual package regions, thereby forming a plurality of semiconductor apparatuses shown in FIG. 10.
The present invention has been made in view of such circumstances. It is an object of the present invention to provide a semiconductor apparatus having a chip mounted on a wiring substrate via an under-fill resin sheet, the semiconductor apparatus being resin sealed with a resin sealing body, wherein a stress applied to a solder terminal formed on the wiring substrate is reduced. It is another object of the present invention to improve the re-flow resistance and prevent a wire from separating from a resin sealing body by effectively exhausting water contained in an under-fill resin sheet to be used.
A semiconductor apparatus of the present invention includes a chip mounted on a wiring substrate via an under-fill resin sheet, the semiconductor apparatus being resin sealed with a resin sealing body, wherein the under-fill resin sheet is greater than the chip size, and its end is exposed from at least one side face of the resin sealing body. Since an end of the under-fill resin sheet is exposed from at least one side face of the resin sealing body, then the water contained in the under-fill resin sheet escapes from an exposed end of the under-fill resin sheet to the outside of the resin sealing body, thus making it possible to improve re-flow resistance of the semiconductor apparatus. When this under-fill resin sheet is substantially identical to the resin sealing body in size, the end of the under-fill resin sheet is exposed from all the side faces of the resin sealing body. Therefore, the water of the under-fill resin sheet escapes to the outside in sufficient quantity, thus making it possible to improve re-flow resistance more remarkably. Even if the size of the under-fill resin sheet is smaller than that of the resin sealing body, and thus, only part of the side face of the resin sealing body is exposed at the end of the under-fill resin sheet, as long as a sufficient quantity of water of the under-fill resin sheet escaping to the outside is ensured, an advantageous effect of the present invention can be attained.
In addition, an under-fill resin sheet with its smaller Young""s modulus than the resin sealing body may be interposed between the resin sealing body and the wiring substrate. In this case, even if there is a difference in thermal expansion coefficient between a wire and a terminal, the stress applied to the wire and terminal is significantly reduced by the under-fill resin sheet.
According to a first aspect of the present invention, there is provided a semiconductor apparatus comprising: a semiconductor chip; a wiring substrate having the semiconductor chip mounted thereon; an under-fill resin sheet interposed between the semiconductor chip and the wiring substrate; and a resin sealing body for sealing the semiconductor chip, the under-fill resin sheet and the wiring substrate, wherein the under-fill resin sheet is greater than the semiconductor chip in size, and its end is exposed from at least one side face of the resin sealing body.
In the semiconductor apparatus according to the first aspect of the present invention, the semiconductor chip may be flip chip connected to the wiring substrate. The under-fill resin sheet may have a thermal expansion coefficient of 30 to 100 pp in a low temperature region ofxe2x80x9455xc2x0 C. and may have a Young""s modulus of 1.0 to 5.4 GPa. The resin sealing body may have a thermal expansion coefficient of 10 to 18 ppm in a low temperature region ofxe2x80x9455xc2x0 C., and may have a Young""s modulus of 10 to 20 GPa. A Young""s modulus of the under-fill resin sheet may be smaller than that of the resin sealing body. The under-fill resin sheet may be exposed at its end from four side faces of the resin sealing body. The under-fill resin sheet may be exposed at its end from two opposite side faces of the resin sealing body, and may not be exposed from the other opposite two side faces. The wiring substrate may be made of a polyimide film. The wiring substrate may be made of glass epoxy. The under-fill resin sheet may be made of an epoxy resin. The semiconductor apparatus may further comprise a mount substrate having the semiconductor chip, the under-fill resin sheet, the wiring substrate, and the resin sealing body mounted thereon. The semiconductor apparatus may further comprise an external terminal interposed between the under-fill resin sheet and the mount substrate. The external terminal may be made of a solder. The semiconductor apparatus may comprise external terminals arranged in an area type and interposed between the under-fill resin sheet and the mount substrate. The external terminals may be made of solder.
In the semiconductor apparatus according to the first aspect of the present invention, the under-fill resin sheet may have a thermal expansion coefficient of 30 to 100 pp in a low temperature region ofxe2x80x9455xc2x0 C. and may have a Young""s modulus of 1.0 to 5.4 GPa. The resin sealing body may have a thermal expansion coefficient of 10 to 18 ppm in a low temperature region ofxe2x80x9455xc2x0 C., and may have a Young""s modulus of 10 to 20 GPa.
In the semiconductor apparatus according to the first aspect of the present invention, the resin sealing body may have a thermal expansion coefficient of 10 to 18 ppm in a low temperature region ofxe2x80x9455xc2x0 C., and may have a Young""s modulus of 10 to 20 GPa.
In the semiconductor apparatus according to the first aspect of the present invention, a Young""s modulus of the under-fill resin sheet may be smaller than that of the resin sealing body.
In the semiconductor apparatus according to the first aspect of the present invention, the under-fill resin sheet may be exposed at its end from four side faces of the resin sealing body.
In the semiconductor apparatus according to the first aspect of the present invention, the under-fill resin sheet may be exposed at its end from two opposite side faces of the resin sealing body, and may not be exposed from the other opposite two side faces.
In the semiconductor apparatus according to the first aspect of the present invention, the wiring substrate may be made of a polyimide film.
In the semiconductor apparatus according to the first aspect of the present invention, the wiring substrate may be made of glass epoxy.
In the semiconductor apparatus according to the first aspect of the present invention, the under-fill resin sheet may be made of an epoxy resin.
In the semiconductor apparatus according to the first aspect of the present invention, the semiconductor apparatus may further comprise a mount substrate having the semiconductor chip, the under-fill resin sheet, the wiring substrate, and the resin sealing body mounted thereon. The semiconductor apparatus may further comprise an external terminal interposed between the under-fill resin sheet and the mount substrate. The external terminal may be made of a solder. The semiconductor apparatus may comprise external terminals arranged in an area type and interposed between the under-fill resin sheet and the mount substrate. The external terminals may be made of solder.
In the semiconductor apparatus according to the first aspect of the present invention, the semiconductor chip may be connected to the wiring substrate by a bonding wire. The under-fill resin sheet may have a thermal expansion coefficient of 30 to 100 pp in a low temperature region ofxe2x80x9455xc2x0 C. and may have a Young""s modulus of 1.0 to 5.4 GPa. The resin sealing body may have a thermal expansion coefficient of 10 to 18 ppm in a low temperature region ofxe2x80x9455xc2x0 C., and may have a Young""s modulus of 10 to 20 GPa. A Young""s modulus of the under-fill resin sheet may be smaller than that of the resin sealing body. The under-fill resin sheet may be exposed at its end from four side faces of the resin sealing body. The under-fill resin sheet may be exposed at its end from two opposite side faces of the resin sealing body, and may not be exposed from the other opposite two side faces. The wiring substrate may be made of a polyimide film. The wiring substrate may be made of glass epoxy. The under-fill resin sheet may be made of an epoxy resin. The semiconductor apparatus may further comprise a mount substrate having the semiconductor chip, the under-fill resin sheet, the wiring substrate, and the resin sealing body mounted thereon. The semiconductor apparatus may further comprise an external terminal interposed between the under-fill resin sheet and the mount substrate. The external terminal may be made of a solder. The semiconductor apparatus may comprise external terminals arranged in an area type and interposed between the under-fill resin sheet and the mount substrate. The external terminals may be made of solder.
According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor apparatus, comprising the steps of: providing an under-fill resin sheet on an insulation substrate that is a wiring substrate; providing a semiconductor chip on the under-fill resin sheet disposed on the insulation substrate; providing a resin sealing body on the insulation substrate so as to cover at least a part of the semiconductor chip and the under-fill resin sheet; and cutting in units of semiconductor chips a laminate body of the resin sealing body, the sheet, and the insulation substrate so that the end of the sheet is exposed from at least one side face of the resin sealing body.
In the semiconductor apparatus manufacturing method according to the second aspect of the present invention, the under-fill resin sheet may be great as compared with the semiconductor chip in size. The under-fill resin sheet may be exposed at its end from four side faces of resin sealing body. The under-fill resin sheet may be exposed at its end from opposite two side faces of the resin sealing body, and may not be exposed from the other opposite two side faces.
In the semiconductor apparatus manufacturing method according to the second aspect of the present invention, the under-fill resin sheet may be exposed at its end from four side faces of resin sealing body.
In the semiconductor apparatus manufacturing method according to the second aspect of the present invention, the under-fill resin sheet may be exposed at its end from opposite two side faces of the resin sealing body, and may not be exposed from the other opposite two side faces.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.